This reverts commit 81577a79.

Reason for revert: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20-%20shared/10544

Original change's description:
> [serializer] Change deferring to use forward refs
> 
> Now that we have forward references, we can replace the body deferring
> mechanism with forward references to the entire pointer.
> 
> This ensures that objects are always deserialized with their contents
> (aside from themselves maybe holding forward refs), and as a result we
> can simplify the CanBeDeferred conditions which encode the constraint
> that some objects either need immediately have contents, or cannot be
> deferred because their fields are changed temporarily (e.g. backing
> store refs).
> 
> This also means that objects with length fields (e.g. arrays) will
> always have those length fields deserialized when the object is
> deserialized, which was not the case when the body could be deferred.
> This helps us in the plan to make GC possible during deserialization.
> 
> Bug: v8:10815
> Change-Id: Ib0e5399b9de6027765691e8cb47410a2ccc15485
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2390643
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#69760}

TBR=jgruber@chromium.org,leszeks@chromium.org

Change-Id: I7a93a59217a2b38e2157c0f7ffc7ac648590a8d6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10815
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2398535Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69763}